Suction throttling valve



Nov. 22, 1949 w. D. TEAGUE, JR

SUCTION THROTTLING VALVE Filed March 15, 1946' Patented Nov. 22, 1949 I2.488.848 suct on THBOTI'LING vanvn' Y Walter B. In, Alpine, N. 1..alsignor to Bendix. Aviation Corporation, Teterbo'ro, N. 1..

a corporation of Delaware,

Application March 15, 1946, Serial No. 654,656

My invention relates to auction control valves and more particularly tovalves of the throttling type. This application is a continuation inpart as to all common subject matter of my-U. 8. application Serial No.563,769, flied November 16,

- 1944 and of my U. S. application Serial No. 566,-

6'", flied December 5, 1944 and now U. S. Patent No. 2,473,620, grantedJune 21, 1949 and assigned to Bendix Aviation Corporation. The featureclaimed herein including a throttling valve pisa cam. (01. 137-153) tonhaving respective inner and outer guiding surfaces at opposite endsthereof is disclosed but not claimed in the aforenoted U. S. Patent No.2,473,620.

One of. the objects of my invention is to provide such a valve which isof utmost simplicity v and minimum weight and yet. suited for the high-ly sensitive control of a suction pressure, whereby instruments anddevices of high accuracy may be operated to provide high precisionperformance.

Another object of my invention is to provide such a valve which issuited to mass production methods and operating accurately and reliablyin spite of practical tolerance limits, particularly as to theconcentricity of ideally concentric cylindrical parts.

Referring to the drawing, this is a longitudinal view, generally insection, of an air suction throttling valve constructed in accordancewith my invention.

In the form of the invention disclosed by way of example, the valve isan air suction throttling type adapted to be applied in a systemincluding various air-operated instruments and devices. When soemployed, it is located in the system between an air suction pump andthe instrument or device to be operated whereby the air suction on thedevice is regulated to substantially maintain a desired suction, oneexample of its many uses being the control of a constant air suction inthe instrument-suction line of an aircraft or the.

whichisclearoftheadiacentendportiontof 2 the casing l to provide a flowassage between the casing i and the element 4. Element 4 has a pair ofport-openings 1 near its cup-end 6, one appearing in the sectional view,whichare to be throttied to control the flow through the valve and hencethe suction in the instrument line which is coupled with the casing l atits end 3.

The annular piston valve 8 is introduced into the space between. thecylinders 2 and 5 and is constructed to be relatively slidable betweenthem. To enable the use of practical production tolerances, especiallyof concentricity, the piston valve 8 has only its land 9 closely.fitting at the inner surface of the piston and only its land it closelyfitting at the outer surface of the piston, with a substantial axialdistance between the lands and II.

To provide a reference basis for the contr of suction in space II on theinstrument side of the annular piston wall l2, an opening it toatmosphere is made in'the cylindrical wall 2 of casing I, thus admittingatmospheric pressure to the space l4 on the other side of the annularpiston II. To oppose the resultant differential pressure across thepiston I2, spring I! is inserted in the space II with one of its endsabutting casing I and the other endabutting the annular wall I2 ofpiston l. The free length and stiffness of the spring ii are so selectedas to bring the lefthand end of land 9 into throttling relation withport-openings 'I when the suction is at the desired value, a shoulder Iton the large-dameter and element 4 to retain element 4 in position Iafter the parts have been put together in the aforedescribedrelationship. Before being assembled, the mating surfaces at 2 and 4'are coated with a sealing lacquer, for example. After the valve has beentested satisfactorily, the sides are staked over lightly at one place oneach side as shown to retain the pin l'l in position. This constructionprovides an extremely inexpensive and light-weight suction valve whichis both reliable and accurate for effecting precise yet stable suctioncontrol.

In operation, a large increase of the suction in the suction pump linewould result in a like large increase of the suction in the instrumentline and inthespace ll ifthevaivetdidnotmove. Ac-

tually the increase of the suctioninspace II inaaeaeae changes in theform and relative arrangements of the parts,flwhich will now appear tothose skilled in the art, may be made without departing from the scopeof the invention. Reference is, therefore, to be had to the appendedclaims for a definition of the limits of the invention.

What is claimed is:

1. In a throttling valve for fluid flowing through a conduit, thecombination of a casing having a female cylindrical-portion, a maleelement located within said portion and having an approximatelyconcentric and smaller-diameter cylindrical portion with a port-openingtherein, and an annular piston valve of substantial length slidablyfitting both said casing and said element and having closely fittingaxially-spaced raised cylindrical portions only on the inside near oneend and on the outside near the other, said piston portions closely amsaid cylindrical mm of-thecasingandelementonlyon'theinsideof the pistonnear one end thereof and on the outside near the other, and meansbiasing the valve in the direction to tend to uncover the port-openingagainst the force due to the diiferential pressure across the piston.

3. In a throttling valve for fluid flowing through a conduit, thecombination of a generally cylindrical casing having one end connectableto one part of the conduit, a generally cylindrical element having anouter end portion constructed to closely flt within said cylindricalcasing and to be connectable to another part of valve being dispomd tohave its smaller-diameter land portion cooperate with the port-openingin the element to throttle the flow therethrough.

ii. In a throttling valve, the combination of a casing having a femalecylindrical portion, an element mounted at one end-within the casingwith an inner male cylindrical portion of smaller diameter extendingapproximately concentrically within said female portion and its innerend vclosed and clear of the interior 01' the casing, and having aport-opening in its cylindrical wall adjacent its said inner end, thecasing having an opening for a reference pressure in its cylindricalwall adJacent the stated mounting end of the element, an annular pistonvalve located intermediate said openings and having slidable sealing theconduit, said element also having a smaller diameter cup-portion withthe inner end clear of the interior of thecasing and a port-opening inits cylindrical wall adJacent its inner cup-end, fluid-tight means forsecuring said element to said casing, said casing having an opening toatmosphere in its cylindrical wall adjacent said outer end portion ofsaid element, an annular piston valve slidably fltting said casing andelement,'said valve being located intermediate said openings and havingclosely fitting portions only on the inside of the pistonnear one endthereof and on the outside near the other respectively, and a springoperatively connecting said valve with said casing to continuously biasthe valve in the direction to tend to uncover the port-opening againstthe force due to the differential pressure across the piston.

' WALTER D. TEAGUE, JR.

lameness crrap The following references are of record in the flle ofthis patent:

UNITED STATES PA'I'ENTB

